1. Field of the Invention
The present invention relates to a plasma display panel, and more particularly to a connection structure and method of a plasma display panel that electrically connects a panel substrate with a connection member such as anisotropic conductive film or a printed circuit board PCB with the connection member.
2. Description of the Related Art
Recently, the importance of image information has been increased following the development and diffusion of information processing system.
Display means, as the most principal man-machine interface of such image information, is becoming more important.
The display means can be applied to LCD, TV or AV monitor and computer display. Plasma Display Panel (hereinafter “PDP”) among the display means has an advantage of being thin and light and being able to be made into a large size.
The PDP includes a set of a panel to generate electric discharge, a printed circuit board having a drive circuit to control the panel and other devices such as heatproof device.
Anisotropic Conductive Film ACF is used to electrically connect the panel and the printed circuit board.
FIG. 1 is a diagram representing the electrical connection between a panel substrate and a flexible substrate in a general PDP. FIG. 2 is a diagram representing an anisotropic conductive film stuck onto the flexible substrate of FIG. 1. FIG. 3 is a diagram representing the structure of the anisotropic conductive film of FIG. 2.
Referring to FIGS. 1 to 3, a plurality of flexible substrates 2 for signal connection are stuck to a panel substrate 1 of rectangular shape. An anisotropic conductive film ACF 3 is stuck to the end of the flexible substrate 2 in order to adhere the panel substrate 1 to the flexible substrate 2, thus the end of the panel substrate 1 and the end of the flexible substrate 2 are stuck to each other and, at the same time, electrically connected to each other.
The anisotropic conductive film 3 used at this moment has a double layer structure of epoxy resin 5 including conductive balls 4 as shown in FIG. 3. Herein, the reference numeral ‘6’ represents PET resin to protect the anisotropic conductive film 3.
FIG. 4 is a diagram representing that a panel substrate is connected to a flexible substrate by use of an anisotropic conductive film of prior art.
As shown in FIG. 4, an anisotropic conductive film 13 and a flexible substrate 14, e.g., Chip On Film COF, Flexible Printed Circuit Film FPC, are mounted on a glass substrate 11.
A silicon rubber 16 is put on the flexible substrate 14 mounted in this way, and then pressure is applied to the flexible substrate 14 by use of a heat compression head 17 of a compressor (not shown). Herein, the silicon rubber 16 is a buffer to prevent the panel substrate 11 from being damaged by the pressure applied by the compressor.
Then, as pressure is applied to the flexible substrate 14, a copper CU electrode 15 and an address electrode 12 of the panel substrate 11 are located having conductive balls 4 therebetween, wherein the conductive balls 4 exist in the anisotropic conductive film 13.
At this moment, the epoxy resin of the anisotropic conductive film 13 fills a space area where the copper electrode 15 and the address electrode 12 are not located, i.e., which is formed between the copper electrodes 15 and between the address electrodes 12.
Accordingly, the panel substrate 11 and the flexible substrate 14 are electrically connected by the conductive balls 4, and they are insulated by the epoxy resin between the copper electrodes 15 and between the address electrodes 12.
However, in case of connecting the panel substrate with the flexible substrate in use of the anisotropic conductive film containing the conductive balls as above, when the epoxy resin of the anisotropic conductive film 13 is pressed upon compression, as shown in FIG. 5, some of the conductive balls 4 dispersed therewithin are used for electrical connection but the others are pushed aside to be gathered at the end of the flexible substrate 14.
In this way, the gathered conductive balls form an electrical line, thereby frequently causing a short circuit.
Also, in the connection structure of prior art that the panel substrate is electrically connected with the flexible substrate by use of the conductive balls, it is possible to be electrically connected by the conductive balls, but such conductive balls cause the cohesiveness of the electrode of the panel substrate and the electrode of the flexible substrate to be weak, so there is high degree of possibility that the connection part breaks away.